ESLint

{
  "parserOptions": {
    "ecmaVersion": 6,
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "rules": {
    "semi": 2
  }
}

• ecmaVersion - set to 3, 5, 6 (or 2015), 7 (or 2016), 8 (or 2017) to specify the ECMAScript version to use. The default value is 5.